Power generating photovoltaic modules are often used with portable electrical equipment. For example, it has been proposed to mount such modules on the exterior of a case containing batteries and an electrically activated device such as a lap top computer. The case itself is oriented by hand with respect to an energizing light source, usually the sun, so that the module can generate electricity to charge the batteries from which the computer is powered.
There is always an optimum orientation of the module with respect to the light source which yields the maximum power output from the module. That optimum orientation is usually when the incident light falls generally perpendicular to the photovoltaic cells of the module, though that may vary depending upon the effect of random reflected light supplementing the direct sunlight.
U.S. Pat. No. 4,551,669 describes photovoltaic modules mounted on a mobile object such as an automobile which as it changes location experiences variations in energizing light and power output. A regulating system is provided which is powered from the cells of the module and which automatically switches the cells between series and parallel connections in response to a signal from a light intensity detector. In doing so the power output of the cells at a given instantaneous position of the automobile on which the module is mounted can be increased depending upon whether a series or a parallel configuration yields a greater output.
The particular purpose of the present invention is twofold. One is to provide a stand system for the module permitting it to be located at the optimum orientation with respect to incident light, as mentioned previously. The other purpose is to provide a multi-volt controller for regulation of electrical energy flow between the photovoltaic module and the electric equipment powered thereby.